Shared And Distributed Memory Implementations Of The Canadian MC2 Model

The Mesoscale Compressible Community (MC2) model is an extension of a fully compressible limited area model developed by Monique Tanguay, Andre Robert and Rene Laprise in the mid-1980's. The model employs a three-timelevel semi-implicit, semi-Lagrangian time discretisation with modified terrain following Gal-Chen coordinates. The semi-implicit scheme results in an elliptic boundary value problem with first-order derivative terms in the vertical direction and thus the resulting discretised system of equations has a large sparse nonsymmetric coefficient matrix. The original alternating direction implicit (ADI) elliptic solver has been replaced with a flexible Generalised Minimum Residual (GMRES) Krylov method with variable preconditioning. We report on the performance of successive over relaxation (SOR) and vertical line relaxation (ADI) as parallel preconditioners to improve the convergence rate of GMRES. Parallelisation of the model for a distributed-memory computing environment has be..

The auxin transport inhibitor response 3 (tir3) allele of BIG and auxin transport inhibitors affect the gibberellin status of Arabidopsis

The Arabidopsis gene BIG (formerly DOC1/TIR3/UMB1/ASA1) is known to encode a huge calossin-like protein that is required for polar auxin transport (PAT). Mutations at this locus, in addition to reducing PAT, can alter the sensitivity of plants to several hormones and light. The tir3-1 allele of BIG reduces the response of plants to application of the gibberellin (GA) precursors ent-kaurenoic acid and GA(12) and its semidwarf phenotype is partially reversed by C-19-GAs. The effects of auxin transport inhibitors (ATIs) on GA 20-oxidation was examined in wild-type and tir3-1 seedlings. 1-N-naphthylphthalamic acid (NPA) and triiodobenzoic acid lead to overexpression of the GA-biosynthetic gene AtGA20ox1 comparable in magnitude to the overexpression observed in seedlings treated with paclobutrazol, a GA biosynthesis inhibitor. In contrast to that of AtGA20ox1, overexpression of AtGA20ox2 is pronounced only in paclobutrazol-treated Col and Ler, and is less in tir3-1 and in all NPA-treated seedlings. Thus the effects of BIG and ATIs on the expression of genes encoding GA 20-oxidases are complex, and suggest that at least in some tissues ATIs, directly or indirectly, may reduce the level of bioactive GA and/or alter GA signal transduction

Meteofan/CRCM6-GEM5.0: First release of CRCM6/GEM5.0

<p>First release</p&gt

Isolation and biological characterization of homoisoflavanoids and the alkylamide n‐p‐coumaroyltyramine from crinum biflorum rottb., an amaryllidaceae species collected in Senegal

Crinum biflorum Rottb. (syn. Crinum distichum) is an Amaryllidaceae plant used in African traditional medicine but very few studies have been performed on this species from a chemical and applicative point of view. Bulbs of C. biflorum, collected in Senegal, were extracted with ethanol by Soxhlet and the corresponding organic extract was purified using chromatographic methods. The pure compounds were chemically characterized by spectroscopic techniques (1D and 2D1H and13C NMR, HR MS and ECD) and X‐ray analysis. Four homoisoflavonoids (1–4) and one alkylamide (5) were isolated and characterized as 5,6,7‐trimethoxy‐3‐(4‐hydroxybenzyl)chroman‐4‐one (1), as 3‐hydroxy‐ 5,6,7‐trimethoxy‐3‐(4‐hydroxybenzyl)chroman‐4‐one (2), as 3‐hydroxy‐5,6,7‐trimethoxy‐3‐(4‐methox-ybenzyl)chroman‐4‐one (3) and as 5,6,7‐trimethoxy‐3‐(4‐methoxybenzyl)chroman‐4‐one (4), and the alkylamide as (E)‐N‐(4‐hydroxyphenethyl)‐3‐(4‐hydroxyphenyl)acrylamide (5), commonly named N‐ p‐coumaroyltyramine. The relative configuration of compound 1 was verified thanks to the X‐ray analysis which also allowed us to confirm its racemic nature. The absolute configurations of compounds 2 and 3 were assigned by comparing their ECD spectra with those previously reported for urgineanins A and B. Flavanoids 1, 3 and 4 showed promising anticancer properties being cytotoxic at low mi-cromolar concentrations towards HeLa and A431 human cancer cell lines. The N‐p‐coumaroyltyra-mine (5) was selectively toxic to A431 and HeLa cancer cells while it protected immortalized HaCaT cells against oxidative stress induced by hydrogen peroxide. Compounds 1–4 also inhibited acetylcho-linesterase activity with compound 3 being the most potent. The anti‐amylase and the strong anti-glucosidase activity of compound 5 were confirmed. Our results show that C. biflorum produces compounds of therapeutic interest with anti‐diabetic, anti‐tumoral and anti‐acetylcholinesterase proper-ties